Desktop Icons reverting to the blue e

[Protronie]

First off, I did search first but did not find what I was looking for.
And yes I know this is slightly O/T but I need help/answers to the aggravating
quirk.

Please forgive posting in wrong place and not using proper names but I'm not a hi tech computer person.

The problem;
When I put a shortcut to C/D (and other sites) on my desktop theres usually the cute little icon ... in C/D's case its the nice orange box with the 47 in it.
Things stay like that for a time but then something (don't know if I do it or the computer does it on its own) the custom icon will revert to that standard i/e icon with the blue e and I have to look hard to find the shortcut I want from all the ones on my desktop that look the same.

How I've been dealing with this;
I usually put up with it and one by one, go to the site, delete the desktop shortcut and reload it again which usually works for a time . This I've put up with since I got my first computer. I'm currently on my second.

I have trouble believing I'm the only person to be dealing with this.

So... could someone out there please explain to me in simple english whats going on and is there some why to fix this problem.

I thank you in advance and steel myself for the flood of "your stupid" post.